Problems loading .357 mag

I am using an RCBS die set with a taper crimp die that has been nothing but a problem from the get go. I've been doing this for a very, very long time and am sick of the problem of trying to get enough crimp to prevent bullets from jumping up, never down. I load full house magnums stuff and granted I don't have any more problems with bullets dislodging, I am getting an occasional colasped case and it aggrevating. I always keep my brass at the same exact length so crimp is equal on every round. But it never fails that because of the worry of bullets jumping up while firing, I try to put as tight a crimp as can be accomplished with the taper. My question is, will a roll crimp give me a better hold on the bullet so I don't have to deal with colapsed case in the batch? When I load 44 mag. the taper cimp is suficient without having to use excessive pressure. What is it about the .357 that makes so prone to this when loading full house stuff?

A roll crimp or REDDING's profile crimp die will help. The profile crimp die both taper and roll crimps. For heavy loads you need to at least go to a substantial roll crimp for max. bullet pull from the cartridge case. The Profile crimp die is the best of both worlds.;)

357 Terms

February 9, 2011, 09:23 PM

I have never used a taper crimp on 357's. I have always used a bullet with a canalure and a good roll crimp.

joneb

February 10, 2011, 12:07 AM

Please share the load details, such as the bullet and brass and charge you are using.

I am using an RCBS die set with a taper crimp die
I only use a taper crimp on non-cannelured plated bullets at lower velocities.

I have found some jacketed bullets to be a bit less than .357". I have found some 357 mag brass to be thinner walled than others, this combination can result in poor case tension on the bullet.

will a roll crimp give me a better hold on the bullet so I don't have to deal with colapsed case in the batch?
If the bullet has a decent cannelure I would use a roll crimp.

I am getting an occasional colasped case and it aggrevating. I always keep my brass at the same exact length
It sounds like you are over crimping, work hardened brass can spring back more than the softer lead and copper.

It could be a problem with your sizing or flare/expanding die, when the bullet is seated in the case can you see a bulge in the case defining the base of the bullet ? or measure the case before seating the bullet and then after, what is the difference ?

winchester1886

February 10, 2011, 12:29 AM

Order you a Lee factory crimp die for the 357.

243winxb

February 10, 2011, 09:40 AM

will a roll crimp give me a better hold on the bullet so I don't have to deal with colapsed case in the batch? A roll crimp should always be used for a 357 mag. in a revolver. The bullets must have a crimp groove. Bullet jump is caused more by neck tension/bullet pull that is to light. Taking measurements of size,expanded, seated brass will tell you if you have enough neck tension. On bullet seating, the case should expand .002" or more.

PapaG

February 10, 2011, 10:25 AM

Roll crimp for sure. If your brass varies in length to any big degree you need to trim also so the crimps are uniform from case to case.

Walkalong

February 10, 2011, 11:04 AM

Check neck tension to make sure you have enough grip on the bullet before the crimp, as no crimp can make up for poor neck tension. A good roll crimp adds to proper neck tension.

Your crimp should end up looking something like these, depending on the bullets crimp groove or cannelure, and which crimp die you use..

Some more crimp pics (http://www.thehighroad.org/showthread.php?t=469815&page=2).
.

Funshooter45

February 10, 2011, 11:13 AM

A roll crimp has always worked well for me. And actually, the roll crimp doesn't have to be severe. I typically worry about putting too much crimp on the .357 rather than not enough. I barely feel the resistance when I apply the roll crimp.

gamestalker

February 10, 2011, 01:48 PM

Hey thanks for the advice on that Redding profile die, looks like that's the direction I'm going in. like I stated I've been doing this a very long time and have had to cope with the issue of the occasional case wall collapsed, and am sick of dealing with it. And since nothing I load for my .357 mag. pistols is other than H110/296 with XTPs or other canelured bullets, I would bet my life will be a little bit less stressful in that area. Since I absolutely love hand loading and every element of it, eliminating this one and only issue will be a nice improvement for this cartridge, and they will also look a little better without that 90 degree crimp from the taper being over applied.

murf

February 10, 2011, 01:59 PM

acceleration. that is what causes the bullet to "jump crimp". think of the guy doing the tablecloth trick where he pulls the tablecloth out from underneath the plates and glasses. he has to pull very quickly (acceleration) to keep the plates and glasses from moving. the higher the acceleration, the more crimp you are going to need. use a good roll crimp that puts the case mouth to the bottom of the canneluer (sp) and go shoot. also, try cleaning the inside of the case, carbon is slick. fwiw

I`ve only loaded revolver ammo with a roll crimp & with the tendencys of todays shooters moving to lead to hold costs down & lead getting softer (cheaper to cast ) the taper & profile dies may be swaging a bit on crimping step !

Steve in PA

February 11, 2011, 02:12 AM

Why would you put a taper crimp on a round that should have a roll crimp??

Been reloading .38/.357 and .44mag for a lot of years, all done using a roll crimp. Never heard of anyone using a taper crimp except for cartridges like 9mm, .45acp, etc.

GP100man

February 11, 2011, 08:13 AM

I think some people get caught up or bit by the "latest & greatest" thing !

What makes it even worse is the manufacturers are in business to sell !

While a tapercrimp/profile crimp has there places I feel it`s not needed for revolver rounnds ,I do advocate trimmin for consistent roll crimp though & I think some use the taper crimp to try & avoid this !

243winxb

February 11, 2011, 09:06 AM

without that 90 degree crimp from the taper being over applied. This statement makes me think you already have a roll crimp die. A roll crimp is standard with RCBS die sets. Check the dies part number.

918v

February 11, 2011, 12:13 PM

If you are seating and crimping at the same time, and you have not adjusted the die correctly, the crimp will dig into the bullet while the seater is still pushing it down and the case wall may collapse.

I would use a seperate crimp die or seperate the seating from the crimping by backing out the die and seating first, then backing out the seater stem and crimping.